MSCI 505
Medical Genetics
COMPLETED EXAM
2024
,1. What are the four types of nucleotides that make up DNA and how do
they pair up to form the double helix? (2 points)
Answer: The four types of nucleotides are adenine (A), thymine (T),
cytosine (C), and guanine (G). They pair up according to the
complementary base pairing rule: A with T and C with G. The two strands
of DNA are held together by hydrogen bonds between the paired bases.
Rationale: This question tests the basic knowledge of the structure and
composition of DNA, which is the main genetic material in humans.
2. What is the difference between a gene and an allele? (2 points)
Answer: A gene is a segment of DNA that codes for a specific protein or
trait. An allele is a variant form of a gene that may have different effects
on the phenotype. For example, the gene for blood type has three alleles:
A, B, and O.
Rationale: This question tests the understanding of the concepts of gene
and allele, which are important for studying inheritance and variation.
3. What is the difference between genotype and phenotype? (2 points)
Answer: Genotype is the genetic makeup of an individual, which
determines the potential traits that can be expressed. Phenotype is the
actual physical appearance or expression of the traits, which may be
influenced by environmental factors. For example, a person may have the
genotype for brown eyes (BB) but have blue eyes as a phenotype due to a
, mutation or epigenetic modification.
Rationale: This question tests the understanding of the concepts of
genotype and phenotype, which are important for studying how genes
interact with the environment.
4. What is the difference between dominant and recessive alleles? (2
points)
Answer: Dominant alleles are those that can mask or override the effect of
another allele in a heterozygous individual. Recessive alleles are those that
can only be expressed when both copies of the gene are the same. For
example, in the gene for earlobe shape, the allele for attached earlobes (a)
is recessive to the allele for free earlobes (A).
Rationale: This question tests the understanding of the concepts of
dominant and recessive alleles, which are important for studying how
traits are inherited.
5. What is the difference between homozygous and heterozygous
individuals? (2 points)
Answer: Homozygous individuals are those who have two identical copies
of an allele for a given gene. Heterozygous individuals are those who have
two different copies of an allele for a given gene. For example, a person
who has two copies of the allele for brown eyes (BB) is homozygous,
while a person who has one copy of the allele for brown eyes and one
copy of the allele for blue eyes (Bb) is heterozygous.
Rationale: This question tests the understanding of the concepts of
homozygous and heterozygous individuals, which are important for
Medical Genetics
COMPLETED EXAM
2024
,1. What are the four types of nucleotides that make up DNA and how do
they pair up to form the double helix? (2 points)
Answer: The four types of nucleotides are adenine (A), thymine (T),
cytosine (C), and guanine (G). They pair up according to the
complementary base pairing rule: A with T and C with G. The two strands
of DNA are held together by hydrogen bonds between the paired bases.
Rationale: This question tests the basic knowledge of the structure and
composition of DNA, which is the main genetic material in humans.
2. What is the difference between a gene and an allele? (2 points)
Answer: A gene is a segment of DNA that codes for a specific protein or
trait. An allele is a variant form of a gene that may have different effects
on the phenotype. For example, the gene for blood type has three alleles:
A, B, and O.
Rationale: This question tests the understanding of the concepts of gene
and allele, which are important for studying inheritance and variation.
3. What is the difference between genotype and phenotype? (2 points)
Answer: Genotype is the genetic makeup of an individual, which
determines the potential traits that can be expressed. Phenotype is the
actual physical appearance or expression of the traits, which may be
influenced by environmental factors. For example, a person may have the
genotype for brown eyes (BB) but have blue eyes as a phenotype due to a
, mutation or epigenetic modification.
Rationale: This question tests the understanding of the concepts of
genotype and phenotype, which are important for studying how genes
interact with the environment.
4. What is the difference between dominant and recessive alleles? (2
points)
Answer: Dominant alleles are those that can mask or override the effect of
another allele in a heterozygous individual. Recessive alleles are those that
can only be expressed when both copies of the gene are the same. For
example, in the gene for earlobe shape, the allele for attached earlobes (a)
is recessive to the allele for free earlobes (A).
Rationale: This question tests the understanding of the concepts of
dominant and recessive alleles, which are important for studying how
traits are inherited.
5. What is the difference between homozygous and heterozygous
individuals? (2 points)
Answer: Homozygous individuals are those who have two identical copies
of an allele for a given gene. Heterozygous individuals are those who have
two different copies of an allele for a given gene. For example, a person
who has two copies of the allele for brown eyes (BB) is homozygous,
while a person who has one copy of the allele for brown eyes and one
copy of the allele for blue eyes (Bb) is heterozygous.
Rationale: This question tests the understanding of the concepts of
homozygous and heterozygous individuals, which are important for
